The present invention relates to a contact arrangement for low-voltage circuit breakers with a pivoted holder for a movable switching lever which is connected to a fixed connection point by a flexible current lead.
A contact arrangement of this kind has become known, for example, through DE-A- No. 1,220,923. Here, in a multi-pole circuit breaker, for each pole a holder with a movable switching lever and a flexible current lead is provided. If, taking this as point of departure, a low-voltage circuit breaker for a higher nominal current is to be developed, the usual method can be followed of providing for each pole, not one, but two or more identical contact levers with respective current leads in a common holder. On these parts, in parallel spatial arrangement and traversed by parallel currents, current forces act which remain without harmful consequences as long as a sufficient distance exists between the parts, as the forces are dependent on the distance. But if the distance is to be as small as possible, as is stipulated for the construction of compact and yet efficient switches, considerable forces must be expected, which most readily affect the parts of greatest mobility. This includes, in particular, the flexible current leads, which precisely in view of least impediment of the mobility of the contact levers, are made as flexible as possible. The current leads are made, for example, of layers of thin copper sheets hardened by rolling, joined at their ends by welding, soldering or other suitable methods. As the current forces act crosswise to the stacking of the sheets, the latter may break or be deformed at their points of attachment, and this may lead to increasing temperature rise and finally to damage to and failure of the circuit breaker.